Hi Lester,

> > With the standard MySQL MyISAM tables, whenever you make a
> > metadata change, MySQL makes a copy of the table, dumps the data
> > and renames the table. Why? Because it are simple files, not a database.
>
> Interesting piece of information Martijn - so they do follow best
> practice ( Which S.Karthick is always to create a copy with the new
> metadata and pump in the old data - but you always have both available
> rather than just dumping the backup ;) )
>
> > When RI is in place, doing the above becomes much harder -- you
> > cannot just delete a table and replace it with a new copy and rename
> > it. When doing that, the RI is broken, pointing to a void area (where
> > your original table used to be).
>
> Martijn do you know who MySQL is handling this in some of the newer
> versions? I thought that new were starting to block metadata changes in
> this case?

I'm unsure in this case... I do know that whenever InnoDB errors
out on you, you will get a cryptic message at best and you need
to ask for the InnoDB status to view the actual error message.

I think that InnoDB still does some kind of copy of the table
structure, work with that and then some...

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server.
Upscene Productions
http://www.upscene.com